4 - How does tone-of-voice effect perception?
It may feel like your logo is the representation of your business but a logo is only one part of your entire brand. When every part of your brand is planned out properly, it forms a strong, cohesive brand and gives the impression of a confident business that knows itself inside and out and that confidence engenders trust from your customers.
How would you feel if you received an email or letter from your bank and the message was full of spelling mistake, grammar errors and overly friendly!? You would immediately suspect that it's a scam/fraudulent message. There's a level of expectation based on the industry itself (banks should be more serious and professional than a nail salon, for instance) logo, colours will add confirmation to the quality of service that you would expect to receive.
The same applies to you and your business, if there are mistakes in your writing it completely undermines your value and just as important, your tone-of-voice: is your brand relaxed and friendly, serious, professional, sombre, fun (a funeral parlour is worlds apart from a cupcake cafe, for example)?